I. Field of the Invention
The present invention relates to the field of burglar alarms for doors and windows, and in particular, to the field of burglar alarms for sliding doors and windows in residences.
II. Prior Art Statement
The following U.S. Patents relate to the field of the present invention. U.S. Pat. No. 2,760,460 relates to a burglar alarm for windows, doors, and other openings. This device comprises a mechanically powered alarm for detecting unauthorized movement of a door knob, a window or a door which results in a mechanically wound spring powered alarm being sounded. The device is fixedly attached to the door or window with a latch for disconnecting the alarm from the adjacent frame member to allow authorized opening of the door or window. No provision is made for adjusting the alarm for the window opening or door opening and no provision is made for readily removing the alarm when it is not needed or for remounting it when it is to be placed in use.
U.S. Pat. No. 3,921,564 discloses a portable burglar alarm having a hand wound spring driven alarm. This device is suitable for burglar protection for doors only. In use the alarm is leaned against the door to be protected and the weight of the device holds the spring driven motor inoperative. When the door is opened, the device falls over and releases the weight of the alarm from the supporting mechanism sounding the alarm.
U.S. Pat. No. 4,059,299 discloses an auxiliary portable lock having an elongated locking bar extending from a housing. The housing has a door engaging element from which the locking bar extends to abut a door casing. An anti-distortion device located within the housing detects any unauthorized movement of the locking bar and sounds an electrical alarm. A key is provided to selectively secure the locking bar to the housing without sounding the alarm, and to allow authorized opening of the door or window without sounding the alarm. All of the elements of this device are not contained within the dwelling to be protected and therefore a knowledgeable burglar can circumvent the protection of this device. Furthermore the device in this instance is not readily removable from the door or window in the event of any emergency.
The above listed U.S. Patent constitute the entire art related to the field of the invention known to the inventor.